V125 - NATIVE SAVE THEN ACCOUNT FILE MOVE - NO BACKUPS

SAVE ACCOUNT CHARACTER:
1. BG2 opens and uses its normal native export panel immediately.
2. BG2 writes the selected character into the normal `characters` folder.
3. Only after SAVE succeeds, the local file mover looks for that exact 1-8 character export stem.
4. That .CHR and matching .BIO are physically moved into characters_<full account name>.
5. Other loose character files in `characters` are never hidden or moved during SAVE.

LOAD ACCOUNT CHARACTER:
1. Loose non-account CHR/BIO files are temporarily moved aside.
2. Only the logged-in account's CHR/BIO files are physically moved from characters_<account> into `characters`.
3. BG2 opens its native import list.
4. Done or Cancel physically moves those files back to characters_<account>, then restores the temporarily held loose files.

No copy, no backup, no restore history, no automatic character respawn.
